The ASON is an optical transport network which completes automatic switching and connection control by a control plane. The architecture of the ASON is divided into three planes: transport plane, control plane and management plane.
As an operating network for providing various services for users, the ASON must have very high reliability, i.e., having strong self-healing and restoration capability. Once there is a fault point, the network will be able to fast adopt other routes or protection modes to ensure that the services running thereon are not influenced or less influenced. Dynamic re-routing restoration is the highlight of the ASON; and services can be restored by the mode of fast re-routing in case of a network fault.
At the same time, different from the traditional optical network, the ASON has a new control plane which can implement the protection switching function of a protection group. The service protection methods for the protection group in the ASON in the related art include: 1. services are protected by a protection group at a ratio of 1:1, wherein such method has certain defects: wasting network resources; and 2. services are protected by the protection group at a ratio of M:N, wherein such method also has certain defects: when M protection connections are all occupied, the M+1th work connection cannot be protected if a fault occurs.
It is an inevitable trend to combine the protection switching mode in the protection group with the dynamic re-routing mode for the services to protect the services in the future. However, new problems will also be caused, i.e., the matching, priority, mutual exclusion and other problems between the two modes. For example, when one work connection in the protection group generates a fault, if the protection switching processing is started at first and the restoration is not performed until the failure of the switching, the precious protection connections will be occupied too early and the protection group will become useless; and if the restoration is started at first and the protection switching process is not started until the failure of the restoration, the network resources will be wasted to a certain extent.
For the matching, priority and mutual exclusion problems between the protection switching mode and the dynamic re-routing mode which are combined to protect services in related technologies, there is still no effective solution.